A nieghbour recently came to me with an iPad - the first I'd seen - asking for help. She knew there were lots of photos on it but couldn't find them. I fiddled for quite a while (I'm not used to smartphones etc either) and suddenly the photos appeared. I believe that somehow the folder they were in had not initially been visible. Could it be that your MAC is looking at the wrong folder?
Oh I know exactly where the photos are to be found on the iPad, sadly, the Mac itself does not see the iPad as an attached device. You can't, for instance go to Finder (mac equivalent to explorer) and navigate the ipad as if it's an external drive. Only iTunes will see it and open it, problem there is, far as I can determine, it only allows a one way transfer, that being, from the Mac to the iPad, and not the otherway around.
Now, I've found an app called "ipad to mac transfer" that will let you move photos and other files in 100 file batches and used it. But, why when I have native iPhoto, iTunes and Image Capture, plus Adobe Bridge Downloader am I forced to install a 5th program to do this? While I really like the iPad for it's compact size and versitility, it seems as if Apple has deliberately crippled it or their engineers are horribly short sighted.